The influence of bottom roughness on the development of lock-release gravity currents is investigated through laboratory experiments using Particle Image Velocimetry. The bottom roughness is represented by arrays of vertical LEGO bricks with a constant spacing while varying \(\lambda \), the relative height of the roughness elements to the gravity current depth. Depending on \(\lambda \), the roughness elements may affect the gravity current propagation: for small \(\lambda \) the current behaves like moving over a smooth bottom, while for larger \(\lambda \) the propagation speed is reduced and the internal structure of the current, including both the head and the tail, is significantly modified. As \(\lambda \) increases, stronger recirculation areas between the roughness elements develop interacting with the overlying layer and giving rise to small-scale vortical structures of opposite sign within the whole depth of the current. The additional drag force induced by the bottom roughness adds significant complexity to the flow dynamics and modifies the characteristics of the current.

通过使用粒子图像测速仪的实验室实验研究了底部粗糙度对解锁重力流发展的影响。底部粗糙度由具有恒定间距的垂直乐高积木阵列表示，同时变化\(\lambda \)，粗糙度元素的相对高度与重力流深度。根据\(\lambda \)，粗糙度元素可能会影响重力电流的传播：对于小的\(\lambda \)，电流的行为就像在平滑的底部上移动，而对于较大的\(\lambda \)，传播速度是减少并且电流的内部结构，包括头部和尾部，都被显着修改。作为\(\lambda \)增加，粗糙元素之间更强的再循环区域与上覆层相互作用，并在电流的整个深度内产生相反符号的小规模涡旋结构。由底部粗糙度引起的额外阻力显着增加了流动动力学的复杂性并改变了电流的特性。